diff --git a/src/Apps/W1/Subcontracting/App/src/Process/Codeunits/SubcProdOFactboxMgmt.Codeunit.al b/src/Apps/W1/Subcontracting/App/src/Process/Codeunits/SubcProdOFactboxMgmt.Codeunit.al
index 3a23e750f4..e8f9440f25 100644
--- a/src/Apps/W1/Subcontracting/App/src/Process/Codeunits/SubcProdOFactboxMgmt.Codeunit.al
+++ b/src/Apps/W1/Subcontracting/App/src/Process/Codeunits/SubcProdOFactboxMgmt.Codeunit.al
@@ -80,6 +80,8 @@ codeunit 99001559 "Subc. ProdO. Factbox Mgmt."
         ProdOrderRoutingLine.SetRange(Status, ProdOrderRoutingLine.Status::Released);
         ProdOrderRoutingLine.SetRange("Prod. Order No.", ProdOrderNo);
         ProdOrderRoutingLine.SetRange("Routing Reference No.", ProdOrderLineNo);
+        ProdOrderRoutingLine.SetRange("Routing No.", RoutingNo);
+        ProdOrderRoutingLine.SetRange("Operation No.", OperationNo);
         exit(ProdOrderRoutingLine.Count());
     end;
 
diff --git a/src/Apps/W1/Subcontracting/Test/src/Codeunits/Tests/SubcSubcontractingTest.Codeunit.al b/src/Apps/W1/Subcontracting/Test/src/Codeunits/Tests/SubcSubcontractingTest.Codeunit.al
index ebed58e81c..df4fb7a651 100644
--- a/src/Apps/W1/Subcontracting/Test/src/Codeunits/Tests/SubcSubcontractingTest.Codeunit.al
+++ b/src/Apps/W1/Subcontracting/Test/src/Codeunits/Tests/SubcSubcontractingTest.Codeunit.al
@@ -2245,6 +2245,54 @@ codeunit 139989 "Subc. Subcontracting Test"
             'Routing Link Code duplicate confirmation must be shown exactly once, not twice');
     end;
 
+    [Test]
+    [HandlerFunctions('DoNotConfirmShowCreatedPurchOrderForSubcontracting')]
+    procedure CalcNoOfProductionOrderRoutingsReturnsOneForSubcontractingPurchaseLine()
+    var
+        Item: Record Item;
+        MachineCenter: array[2] of Record "Machine Center";
+        ProdOrderRoutingLine: Record "Prod. Order Routing Line";
+        ProductionOrder: Record "Production Order";
+        PurchaseLine: Record "Purchase Line";
+        WorkCenter: array[2] of Record "Work Center";
+        SubcProdOFactboxMgmt: Codeunit "Subc. ProdO. Factbox Mgmt.";
+    begin
+        // [SCENARIO 634720] CalcNoOfProductionOrderRoutings must filter by Routing No. and Operation No. so the factbox count matches the drill-down (which is always a single routing line for a subcontracting purchase line).
+
+        // [GIVEN] Manufacturing setup with a routing of multiple operations where only the second work center is subcontracting
+        Initialize();
+        Subcontracting := true;
+        UnitCostCalculation := UnitCostCalculation::Units;
+
+        CreateAndCalculateNeededWorkAndMachineCenter(WorkCenter, MachineCenter);
+        CreateItemForProductionIncludeRoutingAndProdBOM(Item, WorkCenter, MachineCenter);
+
+        // [GIVEN] A Released Production Order whose routing has more than one operation
+        SubcontractingMgmtLibrary.CreateAndRefreshProductionOrder(
+          ProductionOrder, "Production Order Status"::Released, ProductionOrder."Source Type"::Item, Item."No.", LibraryRandom.RandInt(10) + 5);
+
+        ProdOrderRoutingLine.SetRange(Status, ProdOrderRoutingLine.Status::Released);
+        ProdOrderRoutingLine.SetRange("Prod. Order No.", ProductionOrder."No.");
+        Assert.IsTrue(ProdOrderRoutingLine.Count() > 1, 'Test precondition: routing must have more than one operation to detect the bug.');
+
+        UpdateSubMgmtSetupWithReqWkshTemplate();
+
+        // [GIVEN] A Subcontracting Purchase Order created from the routing line of the subcontracting work center
+        SubcontractingMgmtLibrary.CreateSubcontractingOrderFromProdOrderRtngPage(Item."Routing No.", WorkCenter[2]."No.");
+        PurchaseLine.SetRange("Document Type", PurchaseLine."Document Type"::Order);
+        PurchaseLine.SetRange("Prod. Order No.", ProductionOrder."No.");
+#pragma warning disable AA0210
+        PurchaseLine.SetRange("Work Center No.", WorkCenter[2]."No.");
+#pragma warning restore AA0210
+        PurchaseLine.FindFirst();
+
+        // [WHEN] CalcNoOfProductionOrderRoutings is called with the purchase line
+        // [THEN] It returns 1, matching the single routing line shown by the drill-down (not the total operations of the prod order line)
+        Assert.AreEqual(
+          1, SubcProdOFactboxMgmt.CalcNoOfProductionOrderRoutings(PurchaseLine),
+          'CalcNoOfProductionOrderRoutings must equal the number of routing lines opened by the drill-down (exactly one for a subcontracting purchase line).');
+    end;
+
     [Test]
     [HandlerFunctions('DoNotConfirmShowCreatedPurchOrderForSubcontracting,HandleTransferOrder,HandleCreateTransferOrderMsg')]
     procedure PostingDirectSubcontractingTransferSetsSourceFieldsOnDirectTransHeader()